Manufacture of alloys



. desired to Patente'd June 4, 1929.

UNITED STATES 1,716,050.. PATENT OFFICE. I

WILLIAM H, GBOSVENOR ANDVICTOR P. GERSHON, OF NEW YORK, N. Y.; SAID GEE- SHON ASSIGNOB T 0 SAID GROSVENOR.

MANUFACTURE or ALLOYS.

ll'o Drawing.

Our invention relates to improvements in the manufacture of alloys and more particularly to base alloys adapted for the manufacture of white gold and the method of making white gold therewith. As is known in the art, white gold is an alloy of gold, nickel and zinc, some containing also one or more other metals such as copper. or palladium. by melting for .example 15 parts gold and adding to the molten gold and melting therein 4 parts of nickel and 1 part of zinc by wei ht, the whole being covered with a suitafile flux. The main difficulty with this method was that, in spite of the flux, more or less zinc is volatihzed and lost so that the resulting alloy is variable and such variations, particularly in r ect of the quantity of zinc result in an in erior if not useless gold alloy, and only in the hands of skilled manufacturers of alloys is it possible to obtain commercial results, and even then such alloys often contain oxides produced by the oxygen from the air of by regen com ounds caused by the action of hydrogen rom the moisture of the air, which render the alloy excessively brittle. Therefore, the process is not well adagtied for. the avera e jeweller to carry out. ost jewellers, rthermore,prefer to make up their own gold, because the gold the require varies as to number of karate an by makup their own white gold from fine gold ing base metal they can get any karat gold and they desire and do not have to carry in stock substantial quantities of made up gold of different karats involving relatively large carrying charges. To meet this demand of the jewellers, attempts have been made to supply the jewellers with base metals or alloys which the jewellers might readily al loy with fine gold in any desired roportion. The desideratum has been a ase alloy containing nickel and zinc in reportions to makewhite gold. In the mentioned method of making white go by adding the unalloyed nickel and zinc to the molten gold, it 1s known that the zinc should be about one fifth of the base metal, e. g.

if nickel and zinc alone are used to form the base metal to be alloyed with thefine gold, 4 parts of nickel to 1 by weight of zinc would be used, and i for example it were produce an 18 karat white gold,

4 parts nic el and 1 part zinc and 15 parts White gold was formerly made,

white gold is to be obtained.

Application filed February a, 1925. Serial 1T0. 6,540.

of fine gold would be used. A base alloy of about 80% nickel and 20% zinc suitable to be thus alloyed with gold, has not, so far as we are aware, been heretofore produced. It is well known that zinc boils and vaporizes at a temperature well below the melting point of nickel and if nickel be added to molten zinc it is found-that only a relatively small percent e of the nickel will be-taken up, while if zinc be added to molten nickelor the two heated'together to a temperature sufiicient to melt them, a-large part of the zinc volatilizes making it impossible to obtain a resultingnickel-zinc alloy of predetermined composition of anything like the 80-20 proportion, which must be quite closely adhered to in so far as the proportion of zinc is concernedif a satisfactory ,To obtain an alloy which jewellers mi ht 7 melt up with gold to make such white go d, it has been suggested that an alloy containing the zinc and about equal arts of copper and nickel be used. ThlS base alloy contained over 40% cop er. By using this copper it was found t at over 15% and about 40% of nickel of zinc could be gotten in the resulting base alloy of nickel, cop er and zinc. When, however, this base alloy was melted with fine gold to make 18 karat or other usual karat white 'gold, it was found that the resulting gold 'was tinged with 'yellow or red and oil color and did not have that desirable whiteness substantially like that of platinum.

To avoid this and reduce the aniount of copper in the 'resulting gold it has been suggested that two metals be furnished the jewellers, one being merely nickel and the other an alloy of copper and zinc with or without a small amount of nickel and/ or palladium. In this way the amount of copper introduced into the final gold has been reduced to about 10% of the base metal, whereby the resulting old is of much better color. This method has the disadvan e however, that the base metals must be carefully weighed out (as well as the gold) and a mistake in wei hing out either of the two base metals is li ely to result in asubstantial change in the proportion of zinc in the resulting allo wh1ch 1n turn will result in an inferior w 'ite gold if not a useless alloy. Likewise mistakes are frequently made by interchanging one base metal or. alloy for another. Also there is danger of loss of zinc by volatilization, The method is therefore not only inconvenient but quite difficult of manipulation, uncertain in result,

and a single base alloy suitable for melting with fine gold in proportions to make 18 or other usual karat gold has been long sought.

Accordingly in our copending application for U. S. Letters Patent 801'. No. 6539, filed February 3, 1925, now Patent 1,688,642, granted May 8, 1928, we have described a new base metal comprising a substantially uniform and homogeneous alloy containing nickel and zinc or a material containing nickel and zinc alloyed together, the zinc being about 20% of the alloy or material and the nickel about 80%, the alloy or material having the characteristic that when melted and alloyed, for example, with 3 times its weight of fine gold, the resultant gold alloy not only exhibits a whiteness substantially like that of platinum but it is also capable of being cast and rolled for making jewelry. In that application we further disclosed that such a base alloy containing about 20% of zinc can be produced by melting the zinc and nickel under pressure whereby the volatilization of the zinc is prevented so that alloys of nickel and zinc and containing a substantially accurate predetermined percentage of zinc can be satisfactorily obtained. I

While such base alloy is well adapted for the making of white gold as above explained, we have further discovered that the base alloy is much improved if small amounts of certain other metals are included therein such as copper and/or a small amount of gold. By including in the base alloy a small amount of other metal such as about 9% copper, we find that the base alloy may be made under pressures considerably lower than would otherwise be the case. The addition of the small amount of copper in the base alloy results in a base alloy which. when alloyed with fine gold in proportion to make 18 karat or other usual proportion white gold, results in a white gold which is still better ada ted for die stamping and draw-pressing tlian when copper is not used. The qualities of the resulting white gold with respect to rolling, casting, die stamping, etc., we find are also improved if a small quantity .of old be included in the base alloy and for t is purpose we prefer to add about 1% or less of fine gold. If desired the copper may be omitted and only the gold included with the nickel and zinc or vice versa depending on the use to cient. Also the alloying should be carried out in an inert atmosphere preferably an atmosphere of nitrogen, all as described in our said copending application, and preferably with an apparatus such as described in our said copending application.

The resulting base alloy may be readily alloyed with 3 times its weight of fine gold to make 18 karat gold or, any usual proportion and this is easily done by the various jewelers in a manner with which they are accustomed. The resultant gold alloy not only exhibits a whiteness substantially like that of platinum but it is also capable of being readily cast, rolled and stamped for making many kinds of jewelry.

The resultant white gold is also Well adapted for draw-pressing. 1

While we have described our improvements in great detail and in connection with a preferred embodiment thereof, we do not desire to be limited to such details or embodiments since manychanges and modifications may be made and the invention embodied in widely different forms. without departing from the spirit and scope of the improvements in their broader-aspects. Hence we desire to cover all modifications and forms coming within the language or scope of any one or more of the appended claims.

What we claim as new and desire to se cure by Letters Patent is:

1. A material containing zinc, nickel and copper alloyed together, the material containing about 20% of zinc, about 70% or more of nickel and copper in any amount up to 9%.

2. An alloy material containing .zinc, nickel, copper and gold alloyed together,

the material containing about 20% of zinc,

about 70% or more of nickel, copper in any amount up to 9%, and gold.

3. An alloy containing about 20% of zinc, about 9% of copper, about 1% of gold and about 70% of nickel,

In testimony whereof we have signed our names to this specification. v

WILLIAM M. GRQSVENOR. VICTOR P. GERSHON. 

